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The Saving Water, Saving Energy blog provides news, resources and analysis on water, energy, and climate change issues with an emphasis on the inextricable connections between water and energy, also know as the Water-Energy Nexus.

MIT Researchers Find Global Warming Odds Much Worse

Image courtesy / MIT Joint Program on the Science and Policy of Global Change. To illustrate the findings of their model, MIT researchers created a pair of 'roulette wheels.' The wheel on the right depicts their estimate of the range of probability of potential global temperature change over the next 100 years if no policy change is enacted on curbing greenhouse gas emissions. The wheel on the left assumes that aggressive policy is enacted

Posted: 05/21/2009

Author: Bevan Griffiths-Sattenspiel

The first paragraph from a recent Massachusetts Institute of Technology article says it all:

The most comprehensive modeling yet carried out on the likelihood of how much hotter the Earth's climate will get in this century shows that without rapid and massive action, the problem will be about twice as severe as previously estimated six years ago - and could be even worse than that.

So we already knew that climate change was going to be rough, but now MIT researchers are saying that the changes are probably going to be a whole lot worse than we expected. As a climate bill aimed at addressing global warming is currently being debated at the Capitol, this MIT study is a sobering reminder that we need to do something--anything--to begin reducing our carbon emissions.

In 2003, MIT models suggested that warming over the next hundred years would be just 2.4 degrees celsius . Now with better data and more detailed calculations, these new models now predict that warming by 2100 will likely be around 5.2 degrees celsius, with a 90% probability that the warming will fall between 3.5 to 7.4 degrees. In other words, if we don't begin to drastically reducing our carbon emissions soon, it is going to get a heck of a lot warmer on the planet, which means more frequent droughts, more intense floods, dwindling snowpacks, warmer stream flow temperatures and a whole host of other changes to current hydrologic regimes.

Because the effects of global warming will be expressed in our rivers, it is critical for river and watershed groups to understand the anticipated impacts of global warming, prepare for these changes by improving the resiliency of our freshwater resources and do their part to reduce carbon emissions.

While many naysayers of anthropogenic global warming refuse to believe the science, detailed analyses--such as the one conducted by MIT--offer the best look at what we can expect in the future. To get a sense of just how detailed MIT's models are, consider this:

The study uses the MIT Integrated Global Systems Model, a detailed computer simulation of global economic activity and climate processes that has been developed and refined by the Joint Program on the Science and Policy of Global Change since the early 1990s. The new research involved 400 runs of the model with each run using slight variations in input parameters, selected so that each run has about an equal probability of being correct based on present observations and knowledge. Other research groups have estimated the probabilities of various outcomes, based on variations in the physical response of the climate system itself. But the MIT model is the only one that interactively includes detailed treatment of possible changes in human activities as well - such as the degree of economic growth, with its associated energy use, in different countries.

Study co-author Ronald Prinn, the co-director of the Joint Program and director of MIT's Center for Global Change Science, says that, regarding global warming, it is important "to base our opinions and policies on the peer-reviewed science," he says. And in the peer-reviewed literature, the MIT model, unlike any other, looks in great detail at the effects of economic activity coupled with the effects of atmospheric, oceanic and biological systems. "In that sense, our work is unique," he says.